How to see whats beyond the video sequence editor
You may choose to do some of the scrolling in the 3D View first to produce an image sequence, then  later used in the Blender Video Sequence Editor, VSE.  The 3D View can show objects not in the camera.

As another example if a Blender User wanted to have fancy 3D titling that would be created in the 3D View first as an image sequence first.  Simple titling is available in the VSE.

By using planes with a texture and a camera with orthogonal settings you camera will behave more like the VSE.  The texture is the movie or image sequence that has already been created.

I tend to have two scenes.  SceneA, 3D View and Post processing No VSE.  SceneB, VSE only.